IBPS has released an official notice regarding the Normalisation process and formula for Bank Exams. In the notice, it is mentioned that the equipercentile equating method is used to do the normalisation in bank exams.  We have given complete details on this page regarding the IBPS normalisation process. Go through this article to know the IBPS normalisation formula. Also, we have attached the official PDF released by the Institute of Banking & Personnel Selection. So, you can gather full information regarding the normalization process and formula.

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What is Normalisation in Bank Exams?

For any examination, if the number of candidates exceeds the total available capacity of computer nodes at a centre, the examination is conducted in multiple shifts on the same day or across multiple days for a particular post. The candidates are thus administered different sets of questions in each shift. To equate the scores of candidates in different exam sessions, normalization is done.

Download Official PDF About IBPS Normalization Process & Formula in Bank Exams

Equipercentile Equating for Multi-session Objective Type Examinations conducted by IBPS

Equipercentile equating is a statistical method used in psychometrics to ensure score comparability across different test forms.

• This method plays a crucial role in maintaining fairness in candidate evaluation across multiple test sessions.
• Given the necessity of using different test forms due to security concerns and large applicant volumes, equipercentile equating ensures that no candidate is disadvantaged in case of any unintended variations in test difficulty.

Definition and Purpose of Equipercentile Equating Process

Equipercentile equating aligns scores from different test forms by ensuring that scores corresponding to the same percentile rank in one test match the equivalent percentile rank in another test. This method ensures fairness in ranking candidates despite different test forms being used. The approach adheres to international testing standards, ensuring compliance with the principles of equity and fairness.

IBPS Normalisation Formula

The core principle of equipercentile equating relies on cumulative distribution functions (CDFs). Let:

• X - raw score from Test Form A
• Y - raw score from Test Form B
• Fₓ(x) and Fᵧ(y) represent the cumulative distribution functions of X and Y, respectively.

The IBPS normalisation formula, that is, the equipercentile equivalent score Yₑ for a given score X is determined by:

• Yₑ = Fᵧ⁻¹(Fₓ(X))

Where Fᵧ⁻¹ is the inverse of the cumulative distribution function of Test Form B. This ensures that the score X and its equivalent Yₑ represent the same percentile rank in their respective distributions, enabling fair candidate comparisons.

Methodology in IBPS Equating (Normalisation Process)

The IBPS normalisation process of equipercentile equating involves:

1. Computing Score Distributions: Estimate empirical cumulative distributions of different test forms based on recruitment data.
2. Pre-Smoothing Score Distributions: Use log-linear models to smooth score distributions before equating, minimizing noise, and ensuring stable estimates.
3. Selecting the Base Test Session: Choose one test session as the base, based on its statistical properties and stability.
4. Matching Percentile Ranks: Map each score in a given test to its corresponding percentile rank.
5. Determining Equivalent Scores: Identify scores in alternate test forms that match the same percentile rank in the base session.

Example: How Scores Change After Equating?

Consider two test forms, A and B, with different score distributions:

If a candidate scores 50 on Test A, their percentile rank is 85. Using equipercentile equating, we find the score in Test B that corresponds to the 85th percentile, which is 51. This ensures that difficulty variations between test forms do not unfairly impact candidate ranking. In cases where there’s no exactly matching percentile, interpolation is used.

Assumptions and Validity

Population Comparability: Candidate groups across sessions must be similar in ability distribution, ensured by IBPS through randomization and standardized protocols.

Construct Equivalence: Different test forms must measure the same competencies required for the recruitment process.

Practical Justification

Equipercentile equating is a standardized methodology recognized as essential for ensuring non-discriminatory selection processes. Alternative methods like linear equating do not account for distributional differences as effectively.

Empirical Evidence

Extensive studies show that equipercentile equating maintains score fairness. Comparing raw and equated scores confirms that this method successfully normalizes differences across sessions, ensuring equitable assessment and reliability.

As a recognized statistical psychometric technique, equipercentile equating is essential for maintaining fairness in exams conducted in multiple sessions. Its application ensures candidates across sessions are evaluated equitably.

FAQs

Q: What is Normalisation in Bank Exams?

To equate the scores of candidates in different exam sessions, normalization is done.

Q: What Normalization Process is adopted in bank exams?

In bank exams, normalization is done using the Equipercentile equating method to ensure score comparability across different test forms.

Q: What is the IBPS Normalisation formula?

The normalisation formula is, Yₑ = Fᵧ⁻¹(Fₓ(X)).

Here,

• X is the raw score from Test Form A
• Y is the raw score from Test Form B
• Fₓ(x) and Fᵧ(y) represent the cumulative distribution functions of X and Y, respectively.
• Yₑ is the equipercentile equivalent score for a given score X
• Fᵧ⁻¹ is the inverse of the cumulative distribution function of Test Form B.